The invention relates to a voltage-to-current converter comprising a signal resistor formed by a channel of a signal transistor of the field effect type with a source electrode and a drain electrode which form terminals of the channel, and with a set of two adjusting electrodes constituted by first and second adjusting electrodes, one of the two adjusting electrodes being a gate electrode for the purpose of connecting a gate voltage to adjust the channel resistance and the other one of the set of adjusting electrodes being a bulk electrode for the purpose of connecting a bulk voltage, supply means for supplying a source voltage, a drain voltage, first and second adjusting voltages to the source electrode, the drain electrode, the first and second adjusting electrodes respectively, for non-saturated operation of the signal transistor.
A voltage-to-current converter of this type is known, for example, from the article entitled "Fully Integrated Active RC Filters in MOS Technology", IEEE Journal of Solid-State Circuits, Vol. SC-18, No. 6, December 1983, pp. 644-651. Voltage-to-current converters of this type convert a signal voltage to a signal current. In integrated circuits field-effect transistors are used as resistors while the channel of a non-saturated field-effect transistor operating in the triode region operates as a resistor and the signal voltage is applied to the channel. The channel resistance is brought to a desired value by means of the gate voltage.
The channel resistance of such a field-effect transistor is rather non-linear and causes non-linear signal distortion. The second-order distortion is eliminated by using the voltage-to-current converters in a balanced manner. All even-harmonic distortion components are then cancelled. However, the odd-harmonic components continue to be present and limit the dynamic range of the voltage-to-current converter.